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1.
Opt Express ; 21(3): 3083-90, 2013 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-23481766

RESUMO

In this paper, a novel TiO(2) nanoparticle thin film coated optical fiber Fabry-Perot (F-P) sensor had been developed for refractive index (RI) sensing by monitoring the shifts of the fringe contrast in the reflectance spectra. Using in situ liquid phase deposition approach, the TiO(2) nanoparticle thin film could be formed on the fiber surface in a controlled fashion. The optical properties of as-prepared F-P sensors were investigated both theoretically and experimentally. The results indicated that the RI sensitivity of F-P sensors could be effectively improved after the deposition of nanoparticle thin-films. It was about 69.38 dB/RIU, which was 2.6 times higher than that of uncoated one. The linear RI measurement range was also extended from 1.333~1.457 to 1.333~1.8423. More importantly, its optical properties exhibited the unique temperature-independent performance. Therefore, owing to these special optical properties, the TiO(2) nanoparticle thin film coated F-P sensors have great potentials in medical diagnostics, food quality testing, environmental monitoring, biohazard detection and homeland security, even at elevated temperature.


Assuntos
Interferometria/instrumentação , Membranas Artificiais , Nanopartículas/química , Fibras Ópticas , Refratometria/instrumentação , Titânio/química , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento
2.
J Nanosci Nanotechnol ; 11(2): 1297-302, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456175

RESUMO

We have reported first example of 3D hierarchy structure from self-assembly of water-soluble QDs followed by chemical reaction control. After addition of ethylenediaminetetraacetic acid, dipotassium salt dehydrate (EDTA) into L-cysteine-stabilized CdTe QD solution, the color of solution was observed to become lighter and shallower, and finally white precipitates appeared. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results confirm that the morphology transformation from zero dimensional (0D) QDs via two-dimensional (2D) nanoflakes to 3D microflowers occurs among those QD assemblies. Meanwhile, EDX results demonstrate that the as-formed QD-assemblies are not CdTe but CdS. The turnover of chemistry nature from CdTe to CdS after addition of EDTA is mainly due to the oxidation of Te followed by a series of chemical reactions. The photoluminescence (PL) spectroscopy and confocal laser scanning microscopy (CLSM) results reveal that such 3D hierarchy structure of CdS QDs have good optical property.

3.
Neurol Res ; 31(5): 483-9, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19500451

RESUMO

Cerebral hypoxia-ischemia during the perinatal period is the single most important cause of acute newborn mortality and chronic disability. Despite our increasing understanding of the mechanisms of neuronal injury, an effective clinical therapy has yet to be established to mitigate brain damage and improve the prognosis and well-being of these newborn patients. Insulin-like growth factor 1 (IGF-1) is a well-known neurotrophic factor, essential for the survival and functional maturation of immature neurons. This study demonstrated that subcutaneous administration of IGF-1 at 24 and 48 hours of recovery significantly reduced hypoxia-ischemia-induced injury to immature rat brains and improved long-term memory and cognitive behavior. IGF-1's therapeutic effects likely involve its ability to prevent delayed apoptosis, as we demonstrated in primary cortical neuronal cultures under oxygen and glucose deprivation. IGF-1's neuroprotective effects parallel the activities of phosphatidylinositol-3/Akt and its down-stream signaling pathway, suggesting a potential mechanistic link. Overall, evidence from this investigation strongly supports IGF-1's potential therapeutic use in the treatment of hypoxic-ischemic encephalopathy in newborn patients.


Assuntos
Sobrevivência Celular/fisiologia , Citoproteção/fisiologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Fator de Crescimento Insulin-Like I/farmacologia , Fármacos Neuroprotetores/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Western Blotting , Encéfalo/patologia , Lesões Encefálicas/etiologia , Lesões Encefálicas/fisiopatologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citoproteção/efeitos dos fármacos , Feminino , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/prevenção & controle , Aprendizagem em Labirinto/efeitos dos fármacos , Memória , Neurônios/efeitos dos fármacos , Gravidez , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
4.
Mol Med Rep ; 13(6): 5149-56, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27109610

RESUMO

Diabetic nephropathy (DN) is one of the most important causes of end­stage renal disease. Astragaloside IV (AS-IV) is a saponin isolated from Astragalus membranaceus, which possesses various pharmacological activities. AS­IV prevents podocyte apoptosis and ameliorates renal injury in DN; however, few studies have focused on its effects on ion channels. The transient receptor potential channel 6 (TRPC6) is an important Ca2+­permeable ion channel in podocytes, which is involved in high glucose (HG)-induced podocyte apoptosis. The aim of the present study was to investigate whether AS­IV prevented HG­induced podocyte apoptosis via TRPC6. Cultured podocytes were pre­treated with 10, 20 or 40 µM AS­IV for 1 h prior to HG exposure for 24 h. Apoptosis, cell viability, expression of TRPC6, nuclear factor of activated T cells (NFAT2) and B­cell lymphoma 2­associated X protein (Bax), as well as the intracellular Ca2+ concentration were subsequently analyzed. The results indicated that HG induced podocyte apoptosis and upregulation of TRPC6, and increased intracellular Ca2+. Furthermore, enhanced NFAT2 and Bax expression was detected. Conversely, AS­IV protected HG­induced podocyte apoptosis, downregulated TRPC6 expression and suppressed intracellular Ca2+ in HG-stimulated podocytes. AS­IV also suppressed NFAT2 and Bax expression. These results suggest that AS­IV may prevent HG-induced podocyte apoptosis via downregulation of TRPC6, which is possibly mediated via the calcineurin/NFAT signaling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Glucose/metabolismo , Podócitos/metabolismo , Saponinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Canais de Cátion TRPC/biossíntese , Triterpenos/farmacologia , Calcineurina/metabolismo , Linhagem Celular Transformada , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Fatores de Transcrição NFATC/metabolismo , Podócitos/patologia , Canal de Cátion TRPC6
5.
Artigo em Inglês | MEDLINE | ID: mdl-26495017

RESUMO

Background. Uremic pruritus (UP) is a common symptom in patients undergoing maintenance hemodialysis for end-stage renal disease (ESRD). Objective. To determine the clinical efficacy of auricular acupressure therapy on pruritus in hemodialysis patients and to explore possible underlying mechanisms. Methods. Patients receiving maintenance hemodialysis at a referral medical center were recruited and assigned to intervention (n = 32) and control (n = 30) groups. The intervention group underwent auricular acupressure treatment three times a week for six weeks. Auricular acupressure was not applied to patients in the control group. However, tape without Vaccaria seeds was applied to the same six auricular acupoints as the intervention group. Pruritus scores were assessed using VAS scores, and enzyme-linked immunosorbent assays (ELISA) were used to measure levels of other possible contributory biochemical factors. Results. There was a significant difference in mean VAS scores between the postintervention and control groups during follow-up (3.844 ± 1.687 versus 5.567 ± 2.285, F = 22.32, P < 0.0001). Compared to the control group, serum histamine levels in the postintervention group at the six-week follow-up had decreased significantly (F = 5.01, P = 0.0290). Conclusion. Our findings suggest that auricular acupressure may be a useful treatment in the multidisciplinary management of UP in ESRD patients.

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